Flow-based basophil activation test in immediate drug hypersensitivity. An EAACI task force position paper

Diagnosing immediate drug hypersensitivity reactions (IDHRs) can pose a significant challenge and there is an urgent need for safe and reliable tests. Evidence has emerged that the basophil activation test (BAT), an in vitro assay that mirrors the in vivo response, can be a complementary test for many drugs. In this position paper, members of Task Force (TF) "Basophil activation test in the evaluation of Drug Hypersensitivity Reactions" from the European Academy of Allergy and Clinical Immunology (EAACI) present the data from a survey about the use and utility of BAT in IDHRs in Europe. The survey results indicate that there is a great interest for using BAT especially for diagnosing IDHRs. However, there are still main needs, mainly in the standardization of the protocols. Subsequently consensus-based recommendations were formulated for: (i) Technical aspects of BAT in IDHRs including type of sample, management of drugs, flow cytometry protocols, interpretation of the results; and (ii) Drug-specific aspects that should be taken into account when performing BAT in relation to betalactams, neuromuscular blocking agents, fluoroquinolones, chlorhexidine, opioids, radio contrast media, chemotherapeutics, biological agents, nonsteroidal anti-inflammatory drugs, COVID vaccine, and excipients. Moreover, aspects in the evaluation of pediatric population have also been considered. All this indicates that BAT offers the clinician and laboratory a complementary tool for a safe diagnostic for IDHRs, although its place in the diagnostic algorithm depends on the drug class and patient population (phenotype, geography, and age). The standardization of BAT is important for generalizing this method beyond the individual laboratory.

Does Rapid Drug Desensitization to Chemotherapy Affect Survival Outcomes?

BACKGROUND AND OBJECTIVE

Hypersensitivity reactions to oxaliplatin may affect prognosis by jeopardizing the timely completion of scheduled treatment sessions or by forcing reactive patients into unexpected changes in therapy. Rapid drug desensitization (RDD) enables these patients to receive their first-choice treatments safely. However, the possible effects of RDD on the efficacy of oxaliplatin have never been studied. Objective: The objective of this study was to evaluate the effect of RDD on survival rates in oxaliplatin-hypersensitive patients.

METHODS

We performed a 7-year retrospective study to compare survival between oxaliplatin-hypersensitive cases (patients receiving oxaliplatin by RDD) and nonallergic controls (patients receiving standard oxaliplatin infusions). The primary endpoint of this study was overall survival (OS) in cases and controls (Kaplan-Meier method with log-rank test comparisons).

RESULTS

OS was 23.7 months (95%CI, 15.3-30.9) for the 67 cases who underwent 337 RDDs, while for controls (n=143), OS was 34.5 months (95%CI, 21.7-55.5). There were no significant differences between the groups (HR, 1.42; 95%CI, 0.93-2.17; P =.104).

CONCLUSIONS

Survival outcomes of oxaliplatin-hypersensitive patients who received oxaliplatin via RDD did not differ significantly from those of control patients who received oxaliplatin via standard administration. Receiving oxaliplatin by means of RDD might be an effective therapeutic alternative for oxaliplatin-hypersensitive patients.

Delving into cornerstones of hypersensitivity to antineoplastic and biological agents: value of diagnostic tools prior to desensitization

BACKGROUND

Evidence regarding drug provocation test (DPT) with antineoplastic and biological agents is scarce. Our aim was to assess the usefulness of including DPT as a paramount gold standard diagnostic tool (prior to desensitization).

METHODS

Prospective, observational, longitudinal study with patients who, during a 3-year period, were referred to the Desensitization Program at Ramon y Cajal University Hospital. Patients underwent a structured diagnostic protocol by means of anamnesis, skin tests (ST), risk assessment, and DPT. Oxaliplatin-specific IgE was determined in oxaliplatin-reactive patients (who underwent DPT regardless of oxaliplatin-specific IgE results). Univariate analysis and multivariate analysis were used to identify predictors of the final diagnosis among several variables.

RESULTS

A total of 186 patients were assessed. A total of 104 (56%) patients underwent DPT. Sixty-four percent of all DPTs were negative (i.e., hypersensitivity was excluded). Sensitivity for oxaliplatin-specific IgE (0.35 UI/l cutoff point) was 34%, specificity 90.3%, negative predictive value 45.9%, positive predictive value 85%, negative likelihood ratio 0.7, and positive likelihood ratio 3.5.

CONCLUSIONS

These are the first reported data based on more than 100 DPTs with antineoplastic and biological agents (paclitaxel, oxaliplatin, rituximab, infliximab, irinotecan, and other drugs). Implementation of DPT in diagnostic protocols helps exclude hypersensitivity (in 36% of all referred patients), and avoids unnecessary desensitizations in nonhypersensitive patients (30-56% of patients, depending on culprit-drug). Drug provocation test is vital to validate diagnostic tools; consequently, quality data are shown on oxaliplatin-specific IgE and oxaliplatin-ST in the largest series of oxaliplatin-reactive patients reported to date (74 oxaliplatin-reactive patients). Identifying phenotypes and predictors of a diagnosis of hypersensitivity may be helpful for tailored plans.

Hypersensitivity and desensitization to antineoplastic agents: outcomes of 189 procedures with a new short protocol and novel diagnostic tools assessment

BACKGROUND

Desensitization to antineoplastic agents is becoming a standard of care. Efforts to establish and improve these techniques are being made at many institutions. Our aims are to evaluate a new rapid desensitization protocol designed to be shorter (approximately 4 h) and safer (reducing hazardous drugs exposure risks) and to assess the oxaliplatin-specific immunoglobulin E (IgE) as a novel diagnostic tool.

METHODS

Prospective, observational, longitudinal study with patients who, for a 1-year period, suffered reactions to antineoplastic agents and were referred to the Desensitization Program at Ramon y Cajal University Hospital (RCUH). Patients were included or excluded as desensitization candidates after anamnesis, skin testing, risk assessment, and graded challenge. Specific IgE was determined in oxaliplatin-reactive patients. Candidate patients were desensitized using the new RCUH rapid desensitization protocol.

RESULTS

Of 189 intravenous rapid desensitizations, 188 were successfully accomplished in the 23 patients who met inclusion criteria for desensitization (of 58 referred patients). No breakthrough reactions occurred in 94% of desensitizations, and most breakthrough reactions were mild. In 10 oxaliplatin-reactive patients, 38 desensitizations were successfully accomplished. Sensitivity for oxaliplatin-specific IgE was 38% (0.35UI/l cutoff point) and 54% (0.10UI/l cutoff point); specificity was 100% for both cutoff points.

CONCLUSIONS

In the hands of a Desensitization Program, managed by drug desensitization experts, this new protocol has proven an effective therapeutic tool for hypersensitivity to several antineoplastic agents (oxaliplatin, carboplatin, paclitaxel, docetaxel, cyclophosphamide, and rituximab); moreover, it improves safety handling of hazardous drugs. We report the first large series of oxaliplatin desensitizations. Oxaliplatin-specific IgE determination could be helpful.